/*
 * Copyright (C) 2009 M. Hautle.
 * 
 * This file is part of TrackedBean.
 * 
 * TrackedBean is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any later version.
 * 
 * TrackedBean is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License along with TrackedBean. If not, see <http://www.gnu.org/licenses/>.
 */
package ch.trackedbean.binding.action;

import java.util.*;
import javax.swing.*;
import org.jdesktop.observablecollections.*;
import ch.trackedbean.binding.mapping.*;

/**
 * Action for {@link ObservableList} dependent stuff.<br>
 * Use this action if your action is dependent of a list state.<br>
 * Call {@link MappingGroup#createDependentElementBinding(String, IDependentElement)} to map such an action on a {@link MappingGroup}.
 * 
 * @param <T> The content type of the list
 * @author M. Hautle
 */
public abstract class AbstractListDependentAction<T> extends AbstractAction implements IDependentElement, ObservableListListener {
    /** The observed list or null. */
    private ObservableList<T> list;

    /**
     * Default constructor.
     */
    public AbstractListDependentAction() {
    }

    /**
     * Default constructor.
     * 
     * @param name The action name
     * @param icon The action icon
     */
    public AbstractListDependentAction(String name, Icon icon) {
        super(name, icon);
    }

    /**
     * Default constructor.
     * 
     * @param name The action name
     */
    public AbstractListDependentAction(String name) {
        super(name);
    }

    /**
     * Returns the list.
     * 
     * @return The list or null
     */
    public List<T> getList() {
        return list;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    @SuppressWarnings("unchecked")
    public void setDependentValue(Object value) {
        if (!(value == null || value instanceof ObservableList))
            throw new IllegalArgumentException("Only instances of " + ObservableList.class.getName() + " are supported!");
        if (list != null)
            list.removeObservableListListener(this);
        list = (ObservableList) value;
        if (list != null)
            list.addObservableListListener(this);
        listChanged();
    }

    /**
     * Method called if the observed list changes (if it was changed or if an internal change occourd).<br>
     * The return value of this method is used to enable/disable the action.
     * 
     * @param list The list or null (same as {@link #list})
     * @return True if the action has to be enabled
     */
    public abstract boolean listChanged(List<T> list);

    /**
     * The list changed.
     */
    private void listChanged() {
        setEnabled(listChanged(list));
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void listElementPropertyChanged(ObservableList list, int index) {
        listChanged();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void listElementReplaced(ObservableList list, int index, Object oldElement) {
        listChanged();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void listElementsAdded(ObservableList list, int index, int length) {
        listChanged();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void listElementsRemoved(ObservableList list, int index, List oldElements) {
        listChanged();
    }
}
